Percussive hand-tool.



PATENTED MAR. 14, 1905.

H. POTTER. PERGUSSIVE HAND TOOL.

APPLICATION FILED DEO. 17, 1904.

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H. POTTER. PERGUSSIVE HAND TOOL.

APPLIUATION FILED No.1?, 1904.

Wn'tnesses v Patented March 14, 1905.

UNITED STATES PATENT OFFICE.

HENRY POTTER, OF. BROMLEY, ENGLAND.

PERCUSSIVE HAND-TOOL.

SPECIFICATION forming part of Letters Patent No. 784,703, dated March 14, 1905.

Application fired December 17, 1904. serial No. 237,307.

To all whom it Hetty concer-71,:

Be it known that I, HENRY POTTER, a subject of the King of Great Britain and Ireland, residing at Bromley, in the county of Kent, England, (whose post-ofice address is 3 Scotts Vil1as,Heathfield Road,Bromley,in the county of Kent, England) have invented an Improved Percussive Hand-Tool; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention consists of an improved fluidpressure-operated percussive hand-tool.

The invention relates principally to a handportable pneumatic hammer in which an automatic distributing-valve is employed, and has for its object to provide a machine of strong and simple construction and great efficiency in working.

The invention consists principally in providing long inlet and outlet or exhaust ports for the admission and exhaust of compressed air to and from the hammer-cylinder whereby a large volume of motive tluid is admitted to the piston throughout practically the whole length of its stroke.

The invention further comprises details and arrangements or combinations of parts, `as hereinafter more fully set forth.

In the accompanying drawings, Figure 1 is a longitudinal sectional elevation of a pneumatic hammer constructed according to this invention. Figs. 2, 3, and 4 are transverse sections of the tool, respectively, on the lines A B, C D, 'and E F, Fig. 1, looking in the direction of the arrows. Fig. 5 is a sectional View of the tool, taken on the line G H, Fig. 3.

Referring to Figs. 1 to 5, inclusive, of the drawings, the hammer-cylinder according to the example shown consists of the front and rear parts 1 and 2, which are coupled together by means of a hinged sleeve 3, 4 and 5 being enlargements, respectively, on the parts 1 and 2 of the cylinder.

6, Fig. 3, is a permanent hinge pivot or pin connecting the two parts of sleeve 3 on one side, and `7 is a removable tapered pin engaging in lugs on the other side of the sleeve 3.

8 is the hammer-piston, which works in a rotatable sleeve 9 in the hammer-cylinder, said sleeve forming the piston-chamber and acting as a distributing-valve for the admission of compressed air to and from either side of the piston. The sleeve 9 according to the construction shown is provided with wings or projections 10 and 11, (see Fig. 3,) the wing 11 being larger than 10. as shown. These wings 10 11 work in a bushing 12, Fig. 3, which consists of rings 13 and 14, Fig. 1, and a sleeve 15, into which said rings may be screwed. The wings 10 and 11 on sleeve 9 work in chambers 16 and 17 (see Fig. 3) in the bushing 12, which latter is fitted in the recess formed by the enlargements 4 and 5 of the two parts 1 and 2 of the cylinder.

18, Fig. 1, is the hammer-handle, which may be of any known or convenient kind.

19 is the live-air-inlet passage leading from the source of supply through the handle 18.

2O and 21 are constant live-air passages leading from the passage 19 through the cylinderwal] and extending to the forward end of the piston-chamber.

22 and 23, Figs. 3 and 5, are tubular pins connecting the parts 13 and 14 of the valvebushing 12, the passages through said pins respectively forming part of the live-air passages 20 and 21.

24 and 25 are live-air-inlet ports which according to this invention consist of longitudinal slots through the wall of the cylinder, said slots communicating, respectively, with the live-air passages 20 and 21. 26 and 27 are inlet and exhaust ports in the sleeve 9, said ports also consisting of longitudinal slots which are adapted to alternately register, respectively, with the slots or inlet-ports 24 and 25 in the cylinder-wall and with the exhaust ports or slots hereinafter referred to. These ports 24, 25, 26, and 27 are more than onehalf of the stroke of the piston in length, so that air may be admitted to the cylinder for the greater part of the stroke of the piston.

28 and 29 are live-air-inlet ports leading', respectively, from the live-air passages 2O and 21 into the front end of the piston-chamber through the elongated ports or slots 30 and 31 inthe sleeve 9 when said sleeve is turned so as to cause the ports 30 31 to register, respectively, with the ports 28 and 29.

32 (see Fig. 1) is a live-air port and passage leading from the live-air-inlet passage 19 to the chamber 16, in which the wing 10 of sleeve 9 works, there being a constant supply of live air through said passage to chamber 16, tendingto hold the sleeve 9 in theposition shown in Fig. 3.

32 is a port leading from the piston-chamber through sleeve 9 into the chamber 17, in which the larger wing 11 of sleeve 9 works, compressed air beingl admitted through said port 32 to chamber 17 duringl the working of the hammer when the piston 8 passes clear of and uncovers port 321L on its forward stroke, andthe compressed air thus admitted to chamber 17 acting' on the wing' 11, which is of larger area than the wing' 10, will overcome the constant pressure on wing 10, so that the sleeve 9 will be partially rotated and the wings 10 and 11 will be moved from the positions shown in Fig. 3 to the opposite sides of the chambers 16 and 17, respectively.

33 and 34, Figs. 1 and 2, are longitudinal exhaust ports or slots in the wall of the cylinder leading' to the atmosphere for exhausting compressed air from the rear end of the piston-chamber, and 35 36 (see Fig. 4) are similar longitudinal exhaust ports or slots through the wal-l of the cylinder leading' to the atmosphere for exhausting' compressed air from the front end of the piston-chamber.

37 is an exhaust-port in sleeve 9, which at the proper time registers with port 38 in the cylinder-wall leading to the atmosphere for the purpose of exhausting compressed air from the chamber 17 and wing 11, as hereinafter described.

38u is a necking or reduced diameter of the piston 8, which when the piston is approaching the end of its rearward stroke makes communication between port 32 and the ports 37 and 38.

As shown in Fig. 4, the exhaust-slots 35 36 in the cylinder-wall lead into exhaust chambers or channels 39 40, respectively, from which channels a series of ports (indicated by the numbers 391L 49) lead to the atmosphere. Similarly, in Fig. 2 the exhaust-slots 33 34 lead into channels 41 42, respectively, and thence to the atmosphere through ports 412L 42, It will be obvious, however, that, if desired, the exhaust ports or slots 33, 34, 35, and 36 may be carried right through the cylinder-wall direct to the atmosphere.

43 is a riveting-tool carried by the front end of the cylinder.

44 is a minute exhaust-port leading from chamber 16 direct to the atmosphere, and 45 is a similar exhaust-port leading from chamber 17 direct to the atmosphere.

The working of the hammer illustrated in Figs. 1 to 5, inclusive, is as follows: With the parts in the position shown the piston y8, Figs. 1 and 5, is approaching the end of its forward stroke, compressed air being admitted from the passage 19 through passages 2O and 21 and ports 24 and 25 in the cylinder-wall and through the ports 26 and 27 in sleeve 9 into the piston-chamber at the back of piston 8, the front end of the piston-chamber being at the same time open to exhaust through the longitudinal slots or ports 30 31 in sleeve 9, the air in front of the piston passingthrough 30, 35, 39, and 39u and through 31, 36, 40, and 40 to the atmosphere. Immediately the rear end of piston 8 uncovers port 32 (see Figs. l, 3, and 5) on its forward stroke compressed air in the piston-chamber at the back of the piston will pass through port 32 into the chamber 17 and there acting on the larger area-wing 11 will turn the sleeve 9, so that the ports 26 27 in said sleeve will be caused to register, respectively, with the exhaustports 33, 41, 41l and 34, 42, 42*1 (see Fig. 2) in the cylinder-wall, while at the saine time the live-air-inlet ports 24 and 25 in the cylinderwall will be closed by the sleeve 9, and the ports 30 and 31, which in the forward stroke of the piston are in communication with the exhaust-ports 35 and 36, respectively, (see Fig. 4,) in the front end of the cylinder, will be caused to register with thel live-air-inlet ports 28 and 29, respectively, so that compressed ai r will now pass direct from the liveair passages 20 and 21 through the ports 28 and 29, respectively, in the cylinder-wall and through the ports 30 and 31 in the sleeve 9 into the front end of the piston-chamber, whereby the piston is given its rearward stroke. 'Vhen the sleeve 9 is turned or rotated by the admission of compressed air from the piston-chamber through port 32a to chamber 17, as above described, the port 37 in sleeve 9 is caused to register with the port 38 in the cylinder-wall, leading direct to the atmosphere; but by the time this has happened and before the pressure in chamber 17 can be reduced sufficiently to allow the constant pressure in chamber 16 acting on wing 10 to overcome the pressure acting on wing 11, and so return the sleeve 9 to the position shown in Fig. 3, the piston 8 will have started on its rearward stroke and closed port 32a, so that the pressure will be retained in chamber 17. As thepiston continues its rearward stroke the port 32L will be uncovered by the right hand or rearward shoulder of necking 38 of the piston, so that the compressed air previously admitted to chamber 17 through port 32", as above described, will pass out of chamber 17 through the said port 32u into the space in the piston-chamber formed by the necking 38a, and when the right-hand or rearward shoulder of necking 38L passes over and uncovers the port 37 in sleeve 9 (which port, as

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above described, is now registering with port 38 in the cylinder-wall leading to the atmosphere) the compressed air will pass from chamber 17 and the space around necking 38n out through ports 37 and 38 to the atmosphere, so that the constant pressure in chamber 16 acting on wing 10 will return the sleeve 9 to the position shown in Fig. 3, whereby compressed air will be again admitted from the live-air passages 2O and 21 through the ports 24 and 25 in the cylinderwall and through ports 26 and 27 in the sleeve 9 into the rear end of the piston-chamber to drive the piston forward again.

/Vhat I claim is- 1. The combination, with a cylinder, oi a tubular distributing-valve arranged in the said cylinder and prevented from sliding longitudinally therein, said cylinder and valve being provided at one end with ports which are longer than one-halt' ot' the stroke of the piston, a piston slidable longitudinally inside the said valve, and means for moving the said valve circumferentiall y to open and close the said ports.

2. The combination, with a cylinder, of a tubular distri beting-valve arranged in the said cylinder and prevented from sliding longitudinally therein, said cylinder and valve being provided at each end with ports which are longer than one-haltl of the stroke of the piston, and the said cylinder having also a longitudinal supply-passagein its sidewall which is connected with the said ports at' each end of it, a piston slidable longitudinally in the said valve, and means for moving the said valve circumferentially to open and close the said ports at the opposite ends of the cylinder alternately.

3. The combination, with a cylinder provided with side chambers, of a tubular distributing-valve arranged in the said cylinder and provided with wings which project into the said chambers and prevent the valve from movinglongitudinally, said cylinder and valve being provided at one end with ports, a piston slidable longitudinally in the said valve, and means for admitting and exhausting pressure Huid to and from the said chambers whereby the said valve is oscillated in the said cylinder to'open and close the said ports.

4. The combination, with a cylinder formed of two sections arranged end to end and provided with recesses at their meeting' ends, means for securing the said cylinder-sections together, and a bush formed of bush-segments arranged in the said recesses and provided with chambers; of a tubular distributing-valve arranged in the said cylinder and provided with wings which project into the said chambers and prevent the valve from moving longitudinally, said cylinder and valve being provided at one end with ports, a piston slidable longitudinally in the said valve, and means 'for admitting and exhausting' pressure fluid HENRY POTTER. fitness1/s:

7. H. TINsoN, WALTER E. RooHn. 

